You'll find linux has less bugs than a lot of commercial software, simply because it is open and anyone can find and fix a bug, not just a small group of paid developers that have agendas put upon them. The reason linux is used for so many back end server systems is that it IS so stable and reliable. Problems with the Kobo reader have nothing to do with linux from what I've seen - it's all what Kobo have done.

Race conditions cannot happen in sleep mode, or when powered off - which is, reportedly, a state in which these devices deplete their batteries.

A rewrite is the last thing you want from Kobo. Writing an OS from scratch is beyond them. Even rewriting their reader code seems to be beyond doing without introducing more bugs than they fix.

The battery stayed at 95% from January 6th, 18:00 until January 7th, 9:30.

I left it in sleep mode, with an epub "active."

Switched it on 24h hours later on January 8th, 9:30... and the battery was at 55%.

That's from 95 to 55% in 24 hours is -1.67% per hour, which is 59.88 hours of sleep time, or only 2.5 days. This time, I really have no clue whatsoever as to why this is happening.

Bad battery after all? But then why did it seem fine yesterday after getting rid of that kepub? Sigh

Maybe it's just the battery meter. It is said that the calibration of the battery meter can take a few cycles to "learn" how the battery behaves and become accurate. If you've only had a few charge discharge cycles, maybe it is still learning?

My Glo battery doesn't last as long as I hoped, I get about 8-9 hours reading time per charge (with WiFi off, light on about half the time), and find myself needing to charge it every second day. It doesn't seem to lose charge while in sleep mode though, just while reading.

My GF's Glo has similar awful battery life. She only uses the light about 1/3 of the time, max, WiFi is always off. She reads probably 2 hours a day.

Charged fully 2 days ago, and it's down to about 1/3 left. We upgraded her from a Touch, which was significantly better. Thought maybe it needed to be re-calibrated, so I did a paperclip reset, but it made no difference.

I'm just getting her to compile some more accurate figures, then firing off a letter to Kobo support for service info.

UPDATE: Jan 17
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3 days after a full charge, it went dead on Sleep mode, WiFi off. Sent the details to Kobo, and they're supposed to be sending me a replacement. I hope it's new/near new, as this one was hosed out-of-the-box.

My GF's Glo has similar awful battery life. She only uses the light about 1/3 of the time, max, WiFi is always off. She reads probably 2 hours a day.

Might not help your GF, but my problem turned out to be the external SD card, I removed it and battery life improved dramatically. Still investigating whether it is the card itself or the Glo at fault.

Edit: I wonder if it is possible to tell from the time it takes to charge whether there is a battery problem? I.e. an abnormally long or short charge time might indicate a dud battery, normal charge time but short battery life might mean battery OK but a problem with the device using too much power. I don't know what the normal charge time is though. Mine takes about 2.5 hours from fully drained to fully charged.

Might not help your GF, but my problem turned out to be the external SD card, I removed it and battery life improved dramatically. Still investigating whether it is the card itself or the Glo at fault.

Edit: I wonder if it is possible to tell from the time it takes to charge whether there is a battery problem? I.e. an abnormally long or short charge time might indicate a dud battery, normal charge time but short battery life might mean battery OK but a problem with the device using too much power. I don't know what the normal charge time is though. Mine takes about 2.5 hours from fully drained to fully charged.

Could be a dud file on the SD card, the device could be going into overdrive trying to process it, when it can't it just keeps trying.

Could be a dud file on the SD card, the device could be going into overdrive trying to process it, when it can't it just keeps trying.

Possibly, but I had no problem with the speed or response of the Glo, and after removing the external SD card I reloaded all the books that were on it from Calibre to the internal card without problem. Anyway the real test will probably have to wait until I get a new card to try out.

Could be a dud file on the SD card, the device could be going into overdrive trying to process it, when it can't it just keeps trying.

I don't think so. When the card is inserted, the device processes the books on the card. While doing this, it displays a black processing screen. Once it finishes processing the books, the screen goes away. After that, there is added processing each time the cover is needed. But, bad books on the card shouldn't affect the battery like during sleep.

I have however seen on my Touch a syndrome where the SD card is recognized; then a few seconds later dismounted. This behavior seems to repeat (and among other things I find that my Touch will never stay in sleep mode with an SD card in place).

Stop the presses. Like any device the Kobo Glo is not good at giving you an acurate detail of it's battery life from the get go. You have to give it a full charge and then let it run until it dies. The software should then start doing a better job of being able to keep track of how long you can go without charging.

I get several weeks out of a charge on mine. All my books are sideloaded (sorry Kobo). I have found issues with it not warning me though that the battery is getting low. I will be reading and suddenly Boom the screen comes up to say plug me in. I have also noticed a difference based on the quality of the charge it recieves. When I tried giving it top ups from emergency battery powered chargers or questionable plugs in foreign countries I had issues with poor battery life and freezing. Once I got my baby back home and charged on a regular adapter it was fine.

Of course certain things will doom your battery life. The biggest is leaving the wifi on. I never bother doing a full power down and I always use the glo light. Mine lives in sleep mode thanks to the sleep cover. It finds a charger once every couple of weeks for a night (when I think of it).